Injector pneumatic sprayer

Abstract

FIELD: pneumatic equipment.SUBSTANCE: invention relates to equipment for pneumatic application of rubber-bitumen mastics and anti-corrosion agents. The invention concerns an injector pneumatic sprayer, which is used as part of a unit for applying rubber-bitumen mastic, which has a compressor, a receiver, a pressure tank, and air and mastic hoses. The pneumatic sprayer comprises a body with a handle and a channel for inlet of compressed air, an air valve with a trigger, a branch pipe with a channel for inlet of mastic under pressure, a shut-off valve with a handle and a return spring, an injector with an outlet pipe and a tip with a nozzle. A bar is attached to the handle of the shut-off valve with a rotary ball valve, which has holes at the lower end for articulation with a rod, which is pivotally connected to a protrusion on the trigger of the air valve. The upper end of the bar is connected to a hook on the body by means of a return spring. The return spring and rod are installed diametrically opposite to the axis of rotation of the ball valve. The tip is equipped with a replaceable plug for closed blowing of the pneumatic sprayer channels and mastic hose through the pressure tank when pressing the air valve trigger.EFFECT: increase in the ease of control of the injector pneumatic sprayer, ensuring the cost-effectiveness of the application process and improving the conditions for servicing the equipment.1 cl, 7 dwg

Description

[0001] The invention relates to equipment for applying a protective coating by pneumatic spraying of rubber-bitumen mastic or anti-corrosion preservative; it can be used in anti-corrosion treatment of automobiles or preservation of working mechanisms of agricultural machinery.

[0002] A liquid sprayer is known in an installation consisting of a compressor with a receiver, a pressure tank with liquid, and containing a housing, a cylinder with a worm core inside for mixing liquid and air, a spray head, a handle with channels for air and liquid, closed by a spool trigger device with flanges and a tail, screws for adjusting the supply of liquid into the grooves of the worm core (see patent RU No. 2 482 927, IPC B05B 7 / 12, 2013).

[0003] Disadvantages of the sprayer: unregulated air pressure supplied to the sprayer and to the pressure tank can lead to an abundant supply of liquid and its loss; adjustment of the flow area of ​​the throughput holes with screws is unacceptable for liquids with a rubber filler, particles of which can accumulate in the crevices near the screws and block the supply of liquid; the pressure of the liquid on the edges of the spool from the tail end creates an axial force when the sprayer is turned on, which can fix the spool in the on position.

[0004] A spray gun is known that contains a body, a handle with a channel for injecting material, a movable nozzle with a spray head and an air inlet valve, a spring-loaded trigger, and a plug for cleaning the channels (see USSR Author's Certificate No. 1130412, IPC B05B 7 / 16, 1983).

[0005] Disadvantages of the spray gun: the lack of a mechanism for adjusting the material flow rate during spraying does not allow for quick adjustment of the material flow rate; the spray gun is difficult to operate with both hands simultaneously; due to the mobility of the nozzle, the material supply may be inadvertently activated when force is applied to the air inlet valve (for example, due to tension on the air hose); the use of manual cleaning of the channels from material residues makes its maintenance difficult.

[0006] The closest known equipment to the claimed one in technical essence and the achieved effect is an injector pneumatic gun for a pressure tank, comprising a housing with a channel for injecting compressed air from a compressor, an air valve with a trigger, a pipe with a channel for injecting a preservative from a pressure tank, a shut-off valve and a handle with a return spring, an injector with an outlet pipe and a nozzle with a spray nozzle (see the article “Results of a study of ejector pneumatic guns for use in preserving agricultural machinery” / authors Petrashev A.I., Klepikov V.V. / published in the journal: Science in Central Russia. 2022. No. 5 (59). pp. 7-19. DOI: 10.35887 / 2305-2538-2022-5-7-19). The pneumatic gun injector consists of a tee, in which a receiving chamber is made for the preservative supplied under pressure, an air nozzle and a mixing chamber in the outlet pipe channel.An injector pneumatic gun complete with a pressure tank is suitable for continuous supply and spraying of auto preservative containing rubber-bitumen mastic, since the dimensions of the holes in the receiving chamber and mixing chamber of the pneumatic gun are several times larger than the rubber crumb in the auto preservative.

[0007] The disadvantages of the well-known pneumatic injection gun include the difficulty of controlling the protective coating application process and the lack of adjustment of the auto-preservative flow rate. To control the flow of compressed air and auto-preservative, the operator must hold the gun with both hands. With one hand, they must press the air valve trigger and with the other, the spring-loaded handle of the shut-off valve, coordinating their opening and closing. Inconsistency in the opening of the air valve and shut-off valve results in the release of unsprayed auto-preservative onto the surface being treated, degrading the coating quality and increasing material loss. The lack of adjustment of the shut-off valve opening also contributes to increased losses of the applied auto-preservative.

[0008] The objective of the claimed invention is to eliminate the above-mentioned disadvantages and thereby improve the ease of operation of the injector pneumatic sprayer in the installation for applying rubber-bitumen mastic, ensure the cost-effectiveness of the application process and improve service conditions.

[0009] The stated task is achieved in that the injector pneumatic sprayer in the installation for applying rubber-bitumen mastic, consisting of a compressor, a receiver, a pressure tank for mastic, air and mastic hoses, and containing a housing with a handle and a channel for injecting compressed air, an air valve with a trigger, a branch pipe with a channel for injecting mastic under pressure, a shut-off valve with a handle and a return spring, an injector with an outlet pipe and a nozzle with a nozzle, according to the invention, a bar is attached to the handle of the shut-off valve with a rotary ball valve, having at the lower end openings for articulation with a rod connected pivotally to a protrusion on the trigger of the air valve, the upper end of the bar is connected by means of a return spring to a hook on the housing, wherein the return spring and rod are installed diametrically opposite relative to the axis of rotation of the ball valve,and the nozzle is equipped with a replaceable plug for closed blowing of the pneumatic sprayer channels and mastic hose through the pressure tank when pressing the trigger of the air valve.

[0010] The shut-off valve handle is equipped with a bar connected to the return spring and the air valve trigger via a rod. This allows the operator to simultaneously turn on and off the mastic and compressed air supply to the pneumatic injection sprayer with one hand. This ensures convenient operation of the pneumatic injection sprayer, cost-effectiveness, and high-quality performance when applying rubber-bitumen mastic.

[0011] Fig. 1 is a schematic illustration of an installation for applying rubber-bitumen mastic; Fig. 2 is an injector pneumatic sprayer in the "off" position, side view; Fig. 3 is an extension element B in Fig. 2, a sectional shut-off valve in the "closed" position; Fig. 4 is view A in Fig. 2, an injector pneumatic sprayer, top view, partial sections; Fig. 5 is an injector pneumatic sprayer in the "on" position, side view; Fig. 6 is an extension element B in Fig. 5, a sectional shut-off valve in the "open" position.

[0012] The rubber-bitumen mastic application unit consists of a compressor 1, a receiver 2, a pressure tank 3 for mastic, an air hose 4, a mastic hose 5, and an injector pneumatic sprayer 6. A filling valve 7, a carrying handle 8, an atmospheric valve 9, a pressure gauge 10, and a discharge valve 11 for mastic are mounted on the pressure tank 3. A support plate 12 is attached to the bottom of the pressure tank 3.

[0013] The cavity of the pressure tank 3 is connected via the air valve 13 and the pressure-reducing valve 14 to the air tee 15, which is connected via the pneumatic hose 16 to the receiver 2 of the compressor 1. The injector pneumatic atomizer 6 is connected via the air hose 4 and the needle valve 17 to the air tee 15, and via the mastic hose 5 is connected to the outlet valve 11 of the pressure tank 3.

[0014] The injector pneumatic sprayer 6 contains a body 18 with a handle 19, having a channel 20 for inlet of compressed air and an air valve 21 with a trigger 22, a shut-off valve 23 on a branch pipe 24 with a channel for inlet of mastic under pressure, an injector 25 with an outlet pipe 26 and a nozzle 27 with a set of replaceable nozzles, including a spray nozzle 28 for applying mastic to open surfaces, a nozzle 29 with a flexible hose for processing hidden cavities and a plug 30.

[0015] A hook 31 for a return spring 32 of a shut-off valve 23 is installed on the body 18. The injector 25 is made in the form of a tee, inside which an air nozzle 33 and an outlet pipe 26 are installed oppositely. The space between the nozzle 33 and the pipe 26 is a receiving chamber 34 for mastic supplied under pressure from the channel of the pipe 24 through the shut-off valve 23. The channel in the outlet pipe 26 is a chamber 35 for mixing the mastic with the air stream.

[0016] The shut-off valve 23 comprises a rotary ball valve 36 with a handle 37 and a rotation limiter 38. A bar 39 is attached to the handle 37, the upper end 40 of which is connected to a hook 31 on the body 18 via a return spring 32.

[0017] At the lower end 41 of the bar 39, at least two holes 42 are made for alternately connecting with a rod 43 having a stop nut 44. The rod 43 is connected by a hinge 45 to a projection 46 on the trigger 22 of the air valve 21. The return spring 32 and the rod 43 are installed diametrically opposite with respect to the axis 47 of the ball valve 36. In the inoperative state, the handle 37 is pressed by the return spring 32 to the rotation limiter 38, and the shut-off valve 23 is in the "closed" position. When the shut-off valve 23 is closed, there is a gap between the hole 42 in the bar 39 and the stop nut 44 on the rod 43.

[0018] The pneumatic injection sprayer works as follows.

[0019] On pressure tank 3, open filler valve 7, atmospheric valve 9, and needle valve 17, and close discharge valve 11 and air valve 13. Rubber-bitumen mastic of working viscosity is poured into pressure tank 3 through filler valve 7. Close filler valve 7 and atmospheric valve 9. Pressure tank 3 is carried by handle 19, together with injector pneumatic sprayer 6, air hoses 4, and mastic hoses 5, to the platform next to the machine being treated. Support plate 12 ensures a stable position of pressure tank 3 even on uneven surfaces. After compressor 1 is turned on, compressed air is supplied at a pressure of 0.4-0.5 MPa from receiver 2 through pneumatic hose 16 to air tee 15 of pressure tank 3. From air tee 15, air passes through open needle valve 17, air hose 4 and enters injector pneumatic nozzle 6 into compressed air inlet channel 20. Using pressure-reducing valve 14, the air pressure for mastic dispensing is regulated in the range of 0.04-0.1 MPa.Open air valve 13 to supply compressed air to pressure tank 3. Use pressure gauge 10 to check the presence of pressure in pressure tank 3.

[0020] To process open panels of the machine with rubber-bitumen mastic, a spray nozzle 28 is attached to the attachment 27. Open the outlet valve 11 on the pressure tank 3, direct the injector pneumatic sprayer 6 to the panel being processed and press the trigger 22. At the beginning, the trigger 22 opens the air valve 21, and air from the channel 20 enters the air nozzle 33, from the opening of which it passes in the form of a jet through the receiving chamber 34 of the injector 25, the mixing chamber 35 of the outlet pipe 26, the attachment 27 and the spray nozzle 28. When the trigger 22 moves, its protrusion 46 through the hinge 45 moves the rod 43, choosing the gap between the thrust nut 44 and the lower end 41 of the bar 39. Then the rod 43 through the thrust nut 44 presses on the lower end 41 of bar 39, turns handle 37, opens ball valve 36 and stretches return spring 32.

[0021] The rubber-bitumen mastic from the pressure tank 3 passes under pressure through the mastic hose 5, the branch pipe 24 with the mastic input channel, the open ball valve 36 and enters the receiving chamber 34 of the injector 25. There, the mastic is captured by the air stream, broken up into drops in the mixing chamber 35 of the outlet branch pipe 26. The formed liquid-air mixture moves through the nozzle 27 to the spray nozzle 28. In the narrow opening of the nozzle 28, the air stream accelerates, dispersing the mastic into small drops, which move in the form of an aerosol to the panel being treated and settle on it, forming a rubber-bitumen coating. The dispersion of the aerosol is adjusted by supplying compressed air, changing the flow area of ​​the needle valve 17. The flow rate of the mastic is adjusted stepwise by connecting the rod 43 with one of the openings 42 in the bar 39. To increase the flow rate of the mastic, the rod 43 is connected with the opening in the bar 39, located closer to the handle 37.

[0022] When trigger 22 of air valve 21 is released, rod 43, under the action of the stretched return spring 32, is displaced in the opposite direction. Return spring 32 rotates handle 37 until it stops against rotation limiter 38 and closes ball valve 36 of shut-off valve 23. Then, air valve 21, released from the pressure of trigger 22, shuts off the air supply to injector 25, and the application process stops.

[0023] When the trigger 22 is rotated and the operator's hand pressure acts through the rod 43 on the handle 37 of the shut-off valve 23, the ball valve 36 rotates, the return spring 32 stretches, and its tension force increases. Due to the fact that the return spring 32 and the rod 43 are installed diametrically opposite with respect to the axis 47 of the ball valve 36, when the handle 37 with the bar 39 is rotated, the arm of the tension force of the return spring 32 decreases with respect to the axis 47 of the ball valve 36 and the arm of the pressing force acting along the rod 43 increases. In this case, the increasing tension force of the spring 32 is compensated by a smaller pressing force of the operator's hand, which facilitates the control of the injector pneumatic sprayer 6.

[0024] To apply mastic to the inner surface of the box-shaped assembly, a flexible hose with a nozzle 29 for treating hidden cavities is attached to attachment 27. Nozzle 29 with the hose is inserted into the service opening of the box-shaped assembly, and the pneumatic injection sprayer 6 is activated by pressing trigger 22 of air valve 21. Gradually withdrawing the hose from the service opening, apply mastic to the inside of the box-shaped assembly.

[0025] Upon completion of the process of applying the rubber-bitumen mastic on tank 3, close air valve 13, open atmospheric valve 9 and release compressed air from pressure tank 3. Then close atmospheric valve 9, fix plug 30 on nozzle 27 and press trigger 22, opening air valve 21 and shut-off valve 23. Compressed air through open air valve 21 and nozzle 33 enters receiving chamber 34 and squeezes mastic from channels of injector 25, shut-off valve 23, branch pipe 24, mastic hose 5 and outlet valve 11 back into pressure tank 3. The end of the process of purging channels of injector pneumatic sprayer 6 and mastic hose 5 is determined by the flow of compressed air into pressure tank 3 from mastic hose 5. As a result, excess air pressure appears in the pressure tank 3, which is monitored by the pressure gauge 10. After the blowdown is completed, the outlet valve 11 is closed on the pressure tank 3 and the atmospheric valve 9 is opened to relieve the blowdown air pressure.Release trigger 22 of pneumatic sprayer 6, closing air valve 21 and shut-off valve 23.

[0026] Thanks to the closed purge of the channels of the pneumatic sprayer 6 and the mastic hose 5, the process of cleaning them from mastic residues is accelerated and its loss is eliminated, thereby improving the servicing conditions of the pneumatic sprayer 6 and the installation as a whole.

[0027] Pneumatic injection gun information

[0028] Designations on drawings

[0029]

Claims

An injector pneumatic sprayer in an installation for applying rubber-bitumen mastic, consisting of a compressor, a receiver, a pressure tank for mastic, air and mastic hoses and containing a housing with a handle and a channel for injecting compressed air, an air valve with a trigger, a branch pipe with a channel for injecting mastic under pressure, a shut-off valve with a handle and a return spring, an injector with an outlet branch pipe and a nozzle attachment, characterized in that a bar is attached to the handle of the shut-off valve with a rotary ball valve, having openings at the lower end for articulation with a rod connected pivotally to a projection on the air valve trigger, the upper end of the bar is connected by means of a return spring to a hook on the housing, wherein the return spring and rod are installed diametrically opposite relative to the axis of rotation of the ball valve, and the nozzle is provided with a replaceable plug for closed purging of the channels of the pneumatic sprayer and the mastic hose through the pressure tank when you press the air valve trigger.

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